References of "Bera, François"
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See detailImpact of climatic factors on the release of E-β-caryophyllene from alginate beads
Daems, Frédéric ULg; Bera, François ULg; Lorge, Stéphanie ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2016), 20(2),

Description of the subject. Alginate beads that release semiochemical compounds are interesting biological control devices used to attract the natural enemies of aphids in infested crops. Little ... [more ▼]

Description of the subject. Alginate beads that release semiochemical compounds are interesting biological control devices used to attract the natural enemies of aphids in infested crops. Little information, however, is available about the impact of climatic factors on the release of semiochemicals from this diffusive system. Objectives. The objective of this scoping study was to investigate the impact of temperature, relative humidity and wind speed, on the release of E-β-caryophyllene from alginate beads. Method. The impact of the three climatic factors on the release of E-β-caryophyllene from alginate beads was evaluated using a Box-Behnken experimental design and a laboratory scale volatile collection system. The influence of relative humidity on bead water content and size, with and without this semiochemical, was also investigated using a gravimetric method and an easy-to-use photographic device, respectively. Results. The results showed that an increase in temperature caused a significant increase in the E-β¬-caryophyllene release rate. Neither relative humidity nor airflow, however, had a significant effect on the release of this semiochemical when relative humidity and wind speed ranged from 33% to 75% and from 6.61 x10-4 m.s-1 to 2.05 x10-2 m.s-1, respectively. The isotherm curves obtained were characteristic of food products and biopolymer materials. The isotherm shapes were not modified by the incorporation of the semiochemical into alginate beads, and showed an important increase in water content when relative humidity values exceeded 85%. Fortunately, this water content increase did not affect bead size, which facilitates the calculation of E-β-caryophyllene release. Conclusion. The present study shows for the first time the impact of the three main climatic factors on the release of E-β-caryophyllene from alginate beads. It allows learning more about how these biological control devices operate in order to optimize future field trials. [less ▲]

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See detailCharacterization of saccharides released during an in vitro pepsin-pancreatin digestion of corn flour using HPAEC-PAD
Odjo, Djosse Psijus Sylvanus ULg; Bera, François ULg; Jacquet, Nicolas ULg et al

in Stärke = Starch (2016), 68

Saccharides released after an in vitro pepsin-pancreatin digestion of corn flour were quantified and characterized using high-performance anion-exchange chromatography coupled with a pulsed amperometric ... [more ▼]

Saccharides released after an in vitro pepsin-pancreatin digestion of corn flour were quantified and characterized using high-performance anion-exchange chromatography coupled with a pulsed amperometric detector (HPAEC-PAD) and two colorimetric approaches (glucose oxidase/ peroxidase assay and the 3,5-dinitrosalicylic acid assay). HPAEC-PAD revealed five major saccharides as the result of in vitro pepsin-pancreatin digestion of corn grain: glucose, isomaltose, maltose, maltotriose, and glucosyl-maltotriose. Concentrations of glucose released as measured by the three methods assessed are similar when the in vitro pepsin-pancreatin digestion is followed by post incubation with amyloglucosidase. This post incubation unfortunately leads to a loss of information about the degree of polymerization of oligosaccharides that can impact their absorption through intestinal tract. HPAEC-PAD gives both qualitative and quantitative information and then seems more suitable for a nutritional appreciation of the digestion of starchy feedstuffs. [less ▲]

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See detailComparative effects of freeze-drying, fluidized bed-drying and heat moisture treatment on the in vitro digestibility of dry matter, starch and protein of corn grain
Odjo, Djosse Psijus Sylvanus ULg; Malumba Kamba, Paul ULg; Migan, Sabé et al

Poster (2015, June 15)

There is some evidence that the chemical composition and nutritional value of corn is variable and may be influenced by heat treatment. This study compares the modifications induced by freeze-drying (as ... [more ▼]

There is some evidence that the chemical composition and nutritional value of corn is variable and may be influenced by heat treatment. This study compares the modifications induced by freeze-drying (as control), fluidized-bed drying and heat-moisture treatment (at 54, 90 and 130°C) of a flint corn grain and flour harvested at two different moisture content (33 and 28%, wet basis) on its digestibility assessed through in vitro methodologies. High temperature applied during fluidized-bed drying and heat-moisture treatment lead to the increase of the in vitro digestibility of dry matter. This is associated to a partial gelatinization of corn starch granules during heat treatments making them more suitable for digestion by porcine pancreatic amylase. This assumption is demonstrated by the increase of the in vitro digestibility of starch recorded with the increase of drying and heat-treatment temperature. It must be noted however, that at the same time, the digestibility of corn proteins decreased, probably because of denaturation undergo by proteins during heat treatment. It seems that there is an interaction between digestion of starch and protein, the corn starch granule being tightly embedded in a protein matrix. The extent of all of these phenomena strongly depends on availability of water which play a key but non clear role in the effect thermal history of corn grain in its nutritive value. [less ▲]

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See detailCould salt-soluble proteins denaturation index (Promatest) of corn grain help to predict in vitro digestibility of dry matter?
Odjo, Djosse Psijus Sylvanus ULg; Abédi, Fidèle; Bukamba, Célestin et al

Poster (2015, March 18)

The Promatest is a quick and reliable test which allows the assessment of the loss of solubility of salt-soluble proteins. It was used as a reference method for the assessment of the thermal shock ... [more ▼]

The Promatest is a quick and reliable test which allows the assessment of the loss of solubility of salt-soluble proteins. It was used as a reference method for the assessment of the thermal shock suffered by grain and is frequently used by the starch industry to monitor starch quality. There is some evidence that protein solubility is associated with energy utilization. It was then believed that the Promatest could be used to predict the nutritional quality of corn grain This study aims to determine if the Promatest could be used to predict the in vitro digestibility of dry matter of corn grain. Almost 80 samples of corn grain dried at different temperature were analyzed for their salt-soluble protein content. The in vitro digestibility of these corn samples was determined with three different in vitro methods which chiefly differ from each other in the time, the buffer and the amount of enzymes used. Results show that there is a strong correlation between the three methods the in vitro digestibility of dry matter determination (r=0.7627, 0.767 and 0.9324). The promatest index seems to be inversely correlated with in vitro digestibility of samples (r = -0.5343, -0.6861 and -0.5921). However, analysis of plots displayed for the promatest index and all in vitro digestibility measures show that Promatest index values of some samples with close in vitro dry matter digestibility can drastically vary suggesting that others factors such as drying temperature and moisture content may be involved. [less ▲]

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See detailImpact of drying and heat treatment on the feeding value of corn. A review
Odjo, Djosse Psijus Sylvanus ULg; Malumba Kamba, Paul ULg; Beckers, Yves ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2015), 19(3), 301-312

Introduction: Corn is the main cereal cultivated in the world. As feedstuffs for broiler chickens, corn grains provide the majority of the animals’ required metabolizable energy and an appreciable amount ... [more ▼]

Introduction: Corn is the main cereal cultivated in the world. As feedstuffs for broiler chickens, corn grains provide the majority of the animals’ required metabolizable energy and an appreciable amount of protein. However, when submitted to high temperature treatment, such as during drying, the feeding value of corn grain may change significantly. This review reports the current knowledge on changes that occur within corn grains during high temperature drying processes, which can impact on the feeding value of the grains. Literature. Studies show that during these high temperature drying processes, structural changes occur within the major components of corn grains, including starch and proteins, which may affect their bioavailability. These changes may have a significant impact on metabolizable energy and zootechnical performance. Drying could also affect the physical traits of corn grains and in turn the feeding behavior of animals. Conclusions. In spite of the importance of grain drying within the corn grain sector, few studies have been devoted to the effect of drying on the feeding value of corn and no consensus has been reached on this subject, possibly because of the different conditions involved in the experiments reported to date. Strict controls over drying conditions and the use of appropriate methods of analysis for a better appreciation of the effects of drying are therefore recommended. [less ▲]

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See detailChemical characterisation and in vitro assessment of the nutritive value of co-products yield from the corn wet-milling process
Malumba Kamba, Paul ULg; Boudry, Christelle ULg; Roiseux, Olivier et al

in Food Chemistry (2015), 166

The chemical characteristics of co-products recovered during a laboratory-scale wet milling procedure as well as that of whole corn flour were characterised and their digestibility and fermentability ... [more ▼]

The chemical characteristics of co-products recovered during a laboratory-scale wet milling procedure as well as that of whole corn flour were characterised and their digestibility and fermentability value determined using a 2 steps in vitro digestibility and fermentation model of the pig digestive tract. Five co-products differing in their chemical composition were collected and analysed. These co-products differed in their in vitro dry matter Digestibility and in their kinetic of fermentation. High coefficients of digestibility were observed for starchy samples, while low coefficients of digestibility were observed for samples rich in lignocellulosic components. Fermentation patterns of samples analysed were different as well as the profile of volatile fatty acids produced during the fermentation. The production of straight-chain fatty acids produced was significantly correlated with the proportion of starch in the sample, while branched-chain fatty acids were correlated to proteins concentration of samples. [less ▲]

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See detailPhysicochemical characterization and in vitro assessment of the nutritive value of starch yield from corn dried at different temperatures
Malumba Kamba, Paul ULg; Odjo, Djosse Psijus Sylvanus ULg; BOUDRY, Christelle et al

in Stärke = Starch (2014), 66

To assess modifications induced in starch granules during high temperature drying of corn grain and their effect on the nutritive value of corn-starch, physicochemical and structural characteristics of ... [more ▼]

To assess modifications induced in starch granules during high temperature drying of corn grain and their effect on the nutritive value of corn-starch, physicochemical and structural characteristics of starch granules from corn grains dried at different temperatures have been determined. Additionally, their in vitro digestibility and fermentation patterns were investigated, using a two steps in vitro model of the pig digestive tract. High drying temperatures induced a partial gelatinization of starch granules and produced a very favorable substrate for porcine pancreatic amylase and led to an altered physical structure which affected the rate and extent of starch granules digestion by gastric and pancreatic enzymes. Starch micrographs showed that granules extracted from corn dried at 130°C were less angular, bigger, and had smoother surface than granules extracted from corn dried at lower temperature. High-temperature drying increased the digestibility of wet-milled starch granules, while the residues of starch from corn dried at lower temperature produced higher volume of gas during their in vitro fermentation, despite their more pronounced crystalline characteristic. The residues from pepsin–pancreatic digestion of overall samples analyzed showed highly degraded and pitted granules or fragmented external shells, starch from corn dried at 130°C being the most degraded. Aforementioned changes of nutritional attributes of starch granules are discussed according to the restructuration occurring within both their amorphous and crystalline phase, as well as to the changes of the granules size and purity. [less ▲]

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See detailPhysicochemical characterization and in vitro assessment of the nutritive value of starch yield from corn dried at different temperatures
Malumba, P.; Odjo, S.; Boudry, Christelle ULg et al

in Stärke = Starch (2014), 66

To assess modifications induced in starch granules during high temperature drying of corn grain and their effect on the nutritive value of corn-starch, physicochemical and structural characteristics of ... [more ▼]

To assess modifications induced in starch granules during high temperature drying of corn grain and their effect on the nutritive value of corn-starch, physicochemical and structural characteristics of starch granules from corn grains dried at different temperatures have been determined. Additionally, their in vitro digestibility and fermentation patterns were investigated, using a two steps in vitro model of the pig digestive tract. High drying temperatures induced a partial gelatinization of starch granules and produced a very favorable substrate for porcine pancreatic amylase and led to an altered physical structure which affected the rate and extent of starch granules digestion by gastric and pancreatic enzymes. Starch micrographs showed that granules extracted from corn dried at 130°C were less angular, bigger, and had smoother surface than granules extracted from corn dried at lower temperature. High-temperature drying increased the digestibility of wet-milled starch granules, while the residues of starch from corn dried at lower temperature produced higher volume of gas during their in vitro fermentation, despite their more pronounced crystalline characteristic. The residues from pepsin–pancreatic digestion of overall samples analyzed showed highly degraded and pitted granules or fragmented external shells, starch from corn dried at 130°C being the most degraded. Aforementioned changes of nutritional attributes of starch granules are discussed according to the restructuration occurring within both their amorphous and crystalline phase, as well as to the changes of the granules size and purity. [less ▲]

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See detailInvestigation on the effect of drying and moisture content on the nutritive value of corn for broiler feeding
Odjo, Djosse Psijus Sylvanus ULg; Malumba Kamba, Paul ULg; Bera, François ULg

Poster (2013, July 02)

Corn (Zea mays L.), the leading cereal grain in the world, is widely used in broiler diet. However, corn composition has been shown to be variable in terms of starch, protein, fibre, oil and amino acid ... [more ▼]

Corn (Zea mays L.), the leading cereal grain in the world, is widely used in broiler diet. However, corn composition has been shown to be variable in terms of starch, protein, fibre, oil and amino acid content . There is some evidence that some external and internal factors could limit or increase corn nutrient digestibility. One such factor may be drying. Indeed, during high temperature drying, corn grains undergo alterations such as stress crack, protein denaturation, change in functional properties of starch recovered, loss of corn kernel millability... The impact of drying on the nutritional value of corn was not clearly established . This research project aims to clarify the most important mechanisms occurring in the grain during drying which impact its nutritive value in order to improve the growth performance of broilers. [less ▲]

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See detailSuitability of the Weibull 4-parameters model to predict the induction phase of α-amylase production during red sorghum malting when a steep in dilute NaOH is used prior to a resteep in a Bacillus subtilis-S499 based treatment
Bwanganga Tawaba, Jean-Claude ULg; Benjamin Pondo Kouadio; Malumba Kamba, Paul ULg et al

in Journal of the Institute of Brewing (2013)

In previous studies, Bacillus subtilis has been used to control mould growth during red sorghum malting. The use of this biocontrol in steeping liquor has been optimized with some success and the combined ... [more ▼]

In previous studies, Bacillus subtilis has been used to control mould growth during red sorghum malting. The use of this biocontrol in steeping liquor has been optimized with some success and the combined use of a 0.2% NaOH steep, followed by a resteep in a Bacillus subtilis-based biocontrol, has been proposed. The sharpness and variability of the β-amylase peak and the higher levels of β-glucanase obtained in the presence of B. subtilis cells were highlighted. In this work, the suitability of the Weibull 4 Parameters Model to predict sorghum malt α-amylase activity during the enzyme induction stage of red sorghum germination has been compared with those of a 2nd Order Polynomial Model and a General Linear Model. Results obtained showed that the Weibull 4 Parameters Model could be used to predict α-amylase activity, with significant goodness of fit when compared to the 2nd Order Polynomial Model and to the General Linear Model. The effects of steeping treatment (combined use of 0.2% NaOH and Bacillus subtilis S499 starters) and the germination temperature are presented. When the Bacillus subtilis culture used as a starter was diluted, the treatment efficacy to develop α-amylase activity was lost. This study also showed that the germination temperature affected the α-amylase activity rate increase during the induction phase. [less ▲]

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See detailEffect of the use of dilute alkaline prior to Bacillus subtilis-based biocontrol steeping and germination conditions on red sorghum malt β-glucanase activities and residual β-glucans
Bwanganga Tawaba, Jean-Claude ULg; Destain, Jacqueline ULg; Malumba Kamba, Paul ULg et al

in Journal of Cereal Science (2013)

Malting is the ideal stage to deal with β-glucans. Their hydrolysis is very important as the diffusion of both hormones and hydrolytic enzymes in the endosperm of germinated grain depend on it. A high ... [more ▼]

Malting is the ideal stage to deal with β-glucans. Their hydrolysis is very important as the diffusion of both hormones and hydrolytic enzymes in the endosperm of germinated grain depend on it. A high malt β-glucanase activity is not a guarantee of an extensive hydrolysis of β-glucans. When Bacillus subtilis is used to control mould growth, red sorghum malt β-glucanase activity (measured using carboxymethylcellulose as the substrate) was improved without significantly affecting the hydrolysis of malt β-glucans. Thus, in order to reduce the residual β-glucans content, soaking in 0.2% NaOH was combined with a biocontrol. Soaking in 0.2% NaOH is recognized as capable of improving grain hydration by opening-up the endosperm cell walls. The combined use of 0.2% NaOH with Bacillus subtilis-based biocontrol treatments during red sorghum malting, leads to malt with increased β-glucanase activity and a significant reduction of residual β-glucans when compared with the 16 h biocontrol steeping without prior steeping in 0.2% NaOH. β-glucanase activity increases with increased germination temperature and time while, conversely, the residual β-glucans content of the malts decreases. Indeed, while the level of β-glucanase was not vastly different between the malts obtained after steeping in distilled water and those obtained after 8 h steeping in 0.2% NaOH followed by 8 h resteeping in distilled water (NaOH+H2O treatment), their residual β-glucans levels differ significantly. Bacillus subtilis-based treatment leads to malt with improved β-(1-3)- and β-(1-4)-glucanase activities without significantly improved malt β-(1-3),(1-4)-glucanase activity. While malts obtained after 84 h germination weren’t significantly different in terms of malt β-(1-3),(1-4)-glucanase activities for all steeping treatments, the use of 0.2% NaOH steeping prior to resteeping led to malts with improved β-glucans content. Combining the steeping in dilute alkaline and biocontrol enables taking advantage of the dilute alkaline effect on residual β-glucans content, due probably to the opening-up the cell walls and the improvement of water uptake, and that of the biocontrol (improvement of β-glucanase synthesis). [less ▲]

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See detailInfluence of drying and hydrothermal treatments on the denaturation of corn proteins
Odjo, Djosse Psijus Sylvanus ULg; Malumba Kamba, Paul ULg; Bera, François ULg

Poster (2013, February 08)

Corn (Zea mays L.) is the most abundant cereal grain produced in the world. It also provides a significant amount of protein in human and animal diets. During drying corn grains undergo several ... [more ▼]

Corn (Zea mays L.) is the most abundant cereal grain produced in the world. It also provides a significant amount of protein in human and animal diets. During drying corn grains undergo several alterations including protein denaturation. A series of studies have been conducted in order to understand mechanisms behind denaturation of corn proteins during drying and heat moisture treatments. Using a laboratory fluidized-bed dryer, a flint corn variety have been dried between 54° and 130°C and subjected to different analyses from a qualitative point of view with a sequential extraction of corn protein fractions and from a quantitative point of view with the modeling of salt-soluble proteins using Promatest assay. Albumin, globulin and zein solubilities dropped significantly when the drying temperature increased. The electrophoretic patterns of zein and glutelin-G1 were not significantly modified, although the solubility of zein was affected by the drying temperature. The analysis of the different protein group solubilities suggested that denaturation mechanisms other than the creation of new disulfide bonds occurred during the drying of corn at high temperature. The study of the effect of heat treatments on the extractability of salt-soluble proteins shows that temperature; moisture content and time of processing greatly influence their kinetic denaturation. Modeling of salt-soluble proteins reveals that the evolution of extractible salt-soluble proteins content of corn kernels during drying at high temperature is more correctly described with a second order kinetic reaction. Investigations continue in order to understand protein denaturation and influence in functional properties and end-use of corn protein-based products. [less ▲]

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See detailThe swelling behaviour of wheat starch granules during isothermal and non-isothermal treatments
Malumba Kamba, Paul ULg; Jacquet, Nicolas ULg; Delimme, Guy ULg et al

in Journal of Food Engineering (2013), 114(2), 199-206

The size of wheat starch granules was measured during isothermal and non-isothermal treatments and fitted using mathematical models in order to elucidate the time–temperatures dependence of the swelling ... [more ▼]

The size of wheat starch granules was measured during isothermal and non-isothermal treatments and fitted using mathematical models in order to elucidate the time–temperatures dependence of the swelling phenomenon and to improve our understanding of the mechanism followed by granules during gelatinization. Upon the onset temperature of gelatinization, starch granules size increase rapidly and tend to reach equilibrium values that depend on the temperature and heating rate applied. The most accurate fitting of granule size observed overall isothermal treatments was obtained with the third-order kinetic and the Weibull empirical models. The activation energy of swelling calculated for isothermal treatment varied between 41 and 318 kJ mol 1, depending on the mathematical model considered. Therefore, without a consensus on the mechanism and order of reaction followed during gelatinization, the meaningful of kinetic parameters calculated using mathematical models seems highly questionable. During non-isothermal treatments at lower heating rate, it seems like a limitation of the swelling capacity of granules was induced. This phenomenon was attributed to restructuration occurred inside of granules. So, forecasting the swelling behaviour of starch granules during non-isothermal treatment has to consider both the time–temperature and the heating rate applied. [less ▲]

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See detailModelling the β-amylase activity during red sorghum malting when Bacillus subtilis is used to control mould growth
Bwanganga Tawaba, Jean-Claude ULg; Bera, François ULg; Thonart, Philippe ULg

in Journal of Cereal Science (2013), 57

Steeping in dilute alkaline (0.2% NaOH) followed by resteeping in biocontrol (starters of Bacillus subtilis S499) has been used during red sorghum malting. The effect of steeping and germination ... [more ▼]

Steeping in dilute alkaline (0.2% NaOH) followed by resteeping in biocontrol (starters of Bacillus subtilis S499) has been used during red sorghum malting. The effect of steeping and germination conditions has been described using 2 functions: a Weibull 4-parameter model combined with a General Linear Model with Logarithm Link with significant goodness. Steeping conditions (combined use of NaOH and Bacillus subtilis S499) affects the synthesis capacity of grain: when Bacillus subtilis culture used in the steeping step is diluted, lnα increases, suggesting a loss of treatment efficacy. The germination temperature affects the β-amylase synthesis rate during the induction phase: the germination temperature increase is accompanied by a decrease of the β-amylase synthesis rate. During the repression phase of β-amylase synthesis, the effect of malting conditions was found to taper. [less ▲]

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See detailInfluence of processing parameters on physicochemical properties of low-trans and trans-free puff pastry margarines
Lefebure, Emilie ULg; Ronkart, Sébastien; Brostaux, Yves ULg et al

in LWT - Food Science and Technology (2013), 51(1), 225-232

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See detailVers une intégration du sorgho comme matière première pour la brasserie moderne (synthèse bibliographique)
Bwanganga Tawaba, J.-C.; Ba, K.; Destain, Jacqueline ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(4), 622-633

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See detailOptimizing red sorghum malt quality when Bacillus subtilis is used during steeping to control mold growth
Bwanganga Tawaba, Jean-Claude ULg; Bera, François ULg; Thonart, Philippe ULg

in Journal of the Institute of Brewing (2012), 118(3), 295-305

Previous work having shown that Bacillus-subtilis-S499-based biocontrol treatments applied without aeration at the steeping stage of red sorghum malting offered good mould reduction but yielded malts with ... [more ▼]

Previous work having shown that Bacillus-subtilis-S499-based biocontrol treatments applied without aeration at the steeping stage of red sorghum malting offered good mould reduction but yielded malts with low levels of key hydrolytic enzymes, we attempted to raise these levels by aerating the steeping liquor, varying the steeping time (from 8 to 40 h) and temperature (from 25 to 35°C), and combining a biocontrol treatment with prior steeping in 0.2% NaOH. Aeration proved particularly important whenever B. subtilis cells were present in the steep liquor. The optimal temperatures for α- and β-amylase were 30 and 25°C, respectively. By increasing the steeping time it was possible to improve the α-amylase activity, but the -amylase activity peaked sharply between 16 and 20 h, depending on the steeping medium. A good compromise was steeping in biocontrol medium for 14 to 16 h at 30°C. Combination steeping treatments (0.2% NaOH for 8 h followed by biocontrol for 8 h) yielded malts of a quality approaching that afforded by dilute alkaline treatment. [less ▲]

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See detailA Semiochemical Slow-release Formulation in a Biological Control Approach to Attract Hoverflies
Heuskin, Stéphanie ULg; Lorge, Stéphanie ULg; Leroy, Pascal ULg et al

in Journal of Environment and Ecology (2012), 3(1), 72-85

E-β-Farnesene, the alarm pheromone of many aphid species, and E-β-caryophyllene are considered as two sesquiterpenes attractive for aphid predators, among which Syrphidae species. Both compounds were ... [more ▼]

E-β-Farnesene, the alarm pheromone of many aphid species, and E-β-caryophyllene are considered as two sesquiterpenes attractive for aphid predators, among which Syrphidae species. Both compounds were formulated in alginate gel beads as slow-release devices in a biological control approach against aphids. Semiochemical diffusion from beads was studied in the laboratory according to abiotic parameters. Efficiency of formulations as hoverfly attractant was demonstrated in field experiments from June to August 2009. The diffusion of semiochemicals from alginate bead formulations was principally limited by high values (>85%) of relative humidity in the air. Temperature also impacts the release of volatile compounds. In field experiments, these two abiotic factors were supposed to highly condition the trapping of hoverflies. These field trappings demonstrated the efficiency of both semiochemical formulations compared to control (formulation without semiochemical) to catch females of Syrphidae during three months. [less ▲]

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See detailInfluence of drying and hydrothermal treatment of corn on the denaturation of salt-soluble proteins and color parameters
Odjo, Sylvanus; Malumba Kamba, Paul ULg; Dossou, Joseph et al

in Journal of Food Engineering (2012), 109(3), 561-570

The effect of heat treatments (drying and hydrothermal treatment) on the extractability of salt-soluble protein (SSP) was assessed using Promatest methodology for corn kernels heated between 60 C and 120 ... [more ▼]

The effect of heat treatments (drying and hydrothermal treatment) on the extractability of salt-soluble protein (SSP) was assessed using Promatest methodology for corn kernels heated between 60 C and 120 C. During drying, the evolution of the grain moisture content is fitted using the analytical solution of Fick equation developed by Crank (1979) for spherical material. The decrease of extractible salt-soluble protein during heating is forecasted using a first and a second order ordinary differential equation. It was found that temperature; moisture content and time of processing greatly influence the kinetic denaturation of SSP of corn kernels. The evolution of extractible SSP content of corn kernels during drying at high temperature is more correctly described with second order kinetic than with the first order kinetic reaction. The Hunterlab color parameters of corn also vary during drying. Lightness and color intensity decrease while yellowness, redness, chroma and hue angle increase through drying time. Most of these Hunterlab color parameters are highly correlated with the salt-soluble proteins content and therefore could be used as indicators of excessive heat treatment and denaturation of salt-soluble proteins in corn kernels [less ▲]

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